Fabric



Sept. 27, 1932. c HOFFACKER 1,879,243

FABRIC Filed June 5, 1931 2 Sheets-Sheet l womtw 7 IraQHo/[bc/rer Z5 96 ab 40 m @IW dttomug Sept. 27, 1932. I. c. HOFFACKER 1,879,243

FABRIC Filed June 5. 1931 2 Sheets-Sheet 2 M H q 69 L IL ll mm m 65' .W I U HEY 67 u 3 Z q 1 3 5?; L; I I255 9007 9 '2 [m C). Ho fi Patented Sept. 27, 1932 UNITED STATES PATENT OFFICE IRA G. HOFFAGKER, OF BALTIMORE, MARYLAND, ASSIGNOR TO MOUNT VERNON- WOODBERRY MILLS, INC., 0F BALTIMORE, MARYLAND, A CORPORATION OF LAND MARY

FABRIC Application filed June 5,

This invention relates to dryer canvas or dryer felt. Its object is to provide a fabric particularly'adaptable for use as a felt or apron for the drying of wet material by carrylng it over drying cylinders, in the manufacture of paper, in laundry, and other industries.

One object is to provide a dryer canvas or felt of such construction as to permit the rapid dissemination of water vapor through it into the atmosphere.

A further object is to provide a dryer canvas or felt which will readily absorb moisture from the wet material and which will permit the rapid evaporation of'such moisture from the reverse side of the felt.

A further general object is to provide a dryer canvas or felt which will be more efficlent in operation and more durable than felts heretofore in use.

The design of the dryer canvas or felts heretofore and now in use is almost uniformly a multiple weave, i. e. two or more plain weave fabrics held together by means of occasional'binder warp or binder filling ends. Such weaves offer comparatively high resistance to the passage of water vapor through them. It is also diflicult'to evaporate rapidly the absorbed water from the interior of such felts. In carrying out the purpose of this invention, I provide a fabric, which permits rapid passa e of water vapor through it, which is relative y smooth and absorbent on the face next the drying cylinder carrying the wet material, and which has an open back permitting rapid evaporation due to the fact that corrugations present large surface areas to the atmosphere. Not only does this canvas or felt provide for rapid dissemination and evaporation but by the use of a core warp to carry the strain, stretch in length and contraction in width, which have been'problem'sin felts heretofore used, are reduced while at the same time the core-warp is.

better protected from burning out by the interposition of the face of the fabric between such core warp and the hot cylinders.

Further objects and advantages will become apparent as the description proceeds.

0 Referring to the accompanying'drawings,

which are made a part hereof and on which similar reference characters indicate similar parts,

Figure 1 is a perspective view of one form of fabric illustrating the principle of my weave,

liigure 2, a section on line 22 of Figure 1, an

Figures 3 to 8 are perspective and sectional views of various fabrics illustrating the principle of the weave of this invention.

In the fabric shown in Figures 1 and 2 there is a central core warp 10 which carries almost the entire tensile strain of-the fabric. The core warp strands are laid parallel in a single plane and are practically without crimp. They may be either plied or cabled. Weft or filling strands are laid across the core warp 10 and lie substantially in two planes on opposite sides of the plane of the core warp1 10. The weft strands are practically wit out crimp. Face warp strands 12, 13 and 14 are woven so that substantially three fourths of their length lies upon one side of the plane of the core and forms a smooth uniformly distributed weave completely covering the core warp on one face while the opposlte face is open and exposes the core warp strands. Following the course of strand 12, it is noted that .this strand passes over upper weft strand 15,

. 18, under upper weft strand 20, over upper weft strand 22 and under lower weft strand 23 beneath the plane of the core warp 10.

Two warp strands .12 and 13 lie'betw'een adjacent core warp strands 10. A third warp strand 14 passes .over upper weft strand 15 under upper weft strand l7and over upper weft strand 18, then under lower wefts'trand 190 19 over upper weft strand 20, under upper weft strand 22, over upper weft strand 24 and under lower weft strand 25. The course of this warp strand is similar to the courses of 12 and 13. It willbe seen that there is a series of face warp strands 12, 13 and 14, two of which lie between adjacent core warp strands 10. Warp strand 26 shown in Figure 1 is the same as warp strand 12 and the series is repeated.

From the construction so far described it will be clear that the clustering of the face warp strands above the plane of the core warp provides a relatively smooth uniformly distributed weave on this side of the fabric. This is the face of the fabric which is positioned against the drying cylinders. The opposite side of the fabric is open, with corrugations similar to a washboard, exposing the core warp 10 to the atmosphere and exposing a large portion of the face-warp strands 12, 13 and 14 as well as the lower weft strands likewise to the atmosphere. The construction permits rapid passage of vapor through the felt and also permits very rapid evaporation of water absorbed by the felt.

From the construction given it will be clear that the core warp 10, which may be made of relatively heavy plied or cabled strands, gives great tensile strength to the fabric. These core warp strands moreover lie substantially in a straight line and are uncrimped due to the fact that the face warp strands 12, 13 and 14 are wovenover the weft strands passing from oneside to the other of the plane of the core warps 10. This feature tends to minimize stretching in length and contraction in width when the fabric is 1 in use. Moreover the fact that the greater 40 portion of the face warp with half of the weft is placed upon the face of the fabric gives a smooth uniformly distributed face which covers the core warp and protects this warp element carrying the strain from burning out, to a much greater extent than in felts heretofore in use.

Many minor variations in the method of carrying out the principle of this construction, such as the relative proportions of the three elements of core warp, face warp and weft, the character of the face weave, etc., may be made in order to meet the particular requirements of various drying operations i QFigs. 3 -weavef;

med th t is t nd p'se I are; upper le eaw t ree 3 3 .e :err riwe tstra jiaa nd ov r eree ef .4 05 ete-.;=T

dj ce Warp? S eed-.1 pa Y 119F ttexstr ml :LJ'QYQFI let e .areitfls aed-r r a S e -Y i et s over upper weft strand 28, under lower weft strand 36, under upper weft strand 37, over lower weft strand 38, under upper weft strand 39, and over lower weft strand 40. Two warp strands 30 and 31 jacent core warp strands 27. The third warp strand 32 passes under upper weft strand 35, over lower weft strand 29, under upper weft strand 28, over lower weft strand 36, over upper weft strand 37, over lower weft strand 38, over upper weft strand 39, and under lower weft strand 40. The fourth warp strand 33 passes under upper weft strand 35, over lower weft strand 29, over upper weft strand 28, over lower weft strand 36, over upper weft strand 37, under lower weft strand 38, under upper weft strand 39, and over lower weft strand 40. It will be noted that each of these strands passes over two adjacent weft strands above the core warp strands 27, then passing down under one lower weft strand, and then upagain and over two adjacent upper weft strands and then passing down again under every fourth weft strand below the plane of core warp strands 27.

It will be seen that there is a series of face warp strands 30, 31, 32, and 33, two of which lie between adjacent core warp strands 27; arp strand 41 shown in Figure 3 is the same as warp strand 30, and the series is repeated.

Figures 5 and 6 show a. further modified weave.

Following the course of strand 42, it is noted that this strand passes over upper weft strand 43, under upper weft strand 44, over upper weft strand 45 and under upper weft strand 46, etc. appearing on the upper or face plane only above the core warp strands 47. It will be noted that this strand passes over and then under adj a-. cent weft strands above the core warp strands 47 The adjacent face warp strand 48 passes over upper weft strands 44 and 45, under lower weft strand 49, over upper weft strands 46 and 50. It will be noted that this strand passes over the two adjacent weft strands above the core warp strand 47, passing down under one lower weft strand and then up again and over two adjacent weft strands, etc. passing down under every. second weft strand below the plane of core warp strands 47. Two warp strands 42 and 48 lie between adjacent core warp strands 47 Warp. strand strand 45 and over upper weft strand,46,-etc. appearing on the upper or face planeionly above the core warp strands47.,5It.will:,be

under adjacent weft strands. above ,the core warp strands 47 The adjacenfi warp strand .52,.passes over upper weft strand,44,, under glower weft strand 53, over uppelIWeft strands. and 46 and under lower weftqstrand 54,

lie between ad- 51 passes under upper weft strand"43,f,over i I; upper weft strand 44, under upper weftl Following,,the. course-of strand 30'.,it f is noted that this strand passes over and ithenj It will be noted that this strand passes over two adjacent weft strands above the core warp strand 47, passing down under one lower weft strand and then up again and over two adjacent weft strands, etc. passing down under every second weft strand below the .plane of core warp strands 47.

It will be seen that there is a series of face warp strands 42, 48, 51 and 52 two of which lie between ad'acent core warp strands Figures 7 and 8 show still a further modified weave.

Following the course of strand 55 it will be noted that this strand passes under lower weft strand 56, under upper weft strand 57, over lower weft strand 58, over upper weft strand 59. over lower weft strand 60, over upper weft strand 61, over lower weft strand 62, under lower weft strand 63, and under lower weft strand 64, etc. The adjacent warp strand 65 passes over lower weft strand 56, under upper weft strand 57 under lower weft strand 58 under upper weft strand 59, over lower weft strand 60, over upper weft strand 61, over lower weft strand 62, over upper weft strand 63, and over lower weft strand 64, etc.

Two face warp strands 55 and 65 he between adjacent core warp strands 66. The third warp strand 67 passes over lower weft strand 56, over upper weft strand 57, over lower weft strand 58, over upper weftstrand 59, over lower weft strand 60, under upper weft strand 61, under lower weft strand 62, under upper weft strand 63, and over lower weft strand 64, etc. The fourth warp strand 68 passes over lower weft strand 56, over upper weft strand 57 over lower weft strand 58, under upper weft strand 59, under lower weft strand 60, under upper weft strand 61, over lower weft strand 62, over upper weft strand 63, and over lower weft strand 64, etc. It will be noted that eachof these strands passes over two adjacent weft strands above the core warp strands 66, then passing down under one lower weft strand, and then up again and over two adjacent upper weft strands and then passing downagain under every fourth weft strand below the plane of core warp strands 66. It will be seen that there is a series of face warp strands 55, 65, 67 and 68, two of which lie between'adjacent core warp strands 66. \Varp strand 69 in Figure 7 is the same as warp strand 55 and the series is repeated. e

It will be obvious to those skilled in the art that various changes may bemade in my device without departing from the spirit of the invention and therefore I do not limit myself to what is shown the drawings and described in thespecification, but only as indicated by the appended claims.

05 Having thus fully described my said invention, what I claim as new and desire to secure by Letters Patent is:

1. A fabric for dryer canvas or felts comprising core warp strands, weft ,or filler strands and face warp strands over and under the weft strands on both planes of thefabric so as toprovide an open corrugated back to the woven fabric, and a relatively 1 smooth uniform face thereon, substantially as set forth.

2. A dryer" canvas or felt comprising a fabric having a relatively smooth uniform face, a high degree of porosity through the fabric, an open back with corrugations, to permit rapid evaporation of water therefrom, said fabric having core warp strands lying in a plane between two planes of weft strands together with face warp strands, the core warp strands being practically uncrimped and thus serving to carry substantially the entire tensile strain on the fabric to limit the elongation of the fabric, substantially as set forth.

3. A dryer canvas or felt comprising a fabric having a relatively smooth uniform face, a high degree of porosity through the fabric, an open back with corrugations to permit rapid evaporation of water therefrom, said fabric consisting of core warp strands lying in a. plane, weft strands lying in planeson opposite sides of the plane of the core wrap strands, and a plurality of face warp strands between each of the core warp strands, said face warp strands being woven over andllnder the weft strands of said planes, the core warp strands serving to sustain substantially the entire tensile strain on the fabric, substantially as set forth.

4. A fabric comprising a center of core warp strands, weft or filler strands positioned 5 at right angles to and in planes on opposite \sides of the core warp strands and face warp strands woven over and under adjacent weft strands above the plane of the core warp strands, alternate face warp strands pass- 11 ing over a pair of adjacent weft strands on the upper side of the core warp and under alternate weft strands on the under side of the plane of the core warp strands, substantially as set forth.

5. A dryer canvas or felt comprising a fabric having a relatively smooth uniform face, a high porosity, an open back with corrugations to permit rapid evaporation of water therefrom, said fabric consisting of core warp strands lying in a plane, weft strands lying in planes on opposite sides of the plane of the core warp strands, and a pair of face warp strands between each of the core warp strands, said face warp strands being woven over and under the weft strands of both of said planes to leave the core warp strands relatively nncrimped, each pair of face warp strands alternating with face warp strands in the adjacent space between adjacent core 133 warp strands to provide a smooth woven face to the fabric, substantially as setforth.

6. A dryer canvas or felt comprising a fabric having a relatively smooth uniform face, a high porosity, an open back with corrugations to ermit rapid evaporation of the water therefi om, said fabric consisting of core warp strands lying in a. plane, weft strands lying in planes on opposite sides of the plane of the core warp strands, and a pair of face warp strands between each of the core warpstrands, said face warp strands being woven over and under the weft strands to said planes to leave the core warp strands,

relatively uncrimped, each pair of face warp strands alternating with face warp strands in the adjacent space between adjacent core warp strands to provide a smooth woven face to the fabric, alternate face warp strands being woven over two weft strands above the plane of the core warp strands and under alv ternate weft strands below the plane of core tively smooth or uniform face to warp strands providing large surface areain contact with the atmosphere to cause rapid evaporation of water from the dryer canvas or felt, substantially as set forth.

' dryer canvas or felt formed with a series of core warp strands, a series of weft strands lying in planes on the opposite sides of the plane of the core warp strands, a face warp strand so woven over theweft strands as to pass over a weft strand above the plane of the core warp strands, under a weft strand below the plane of the core warp strands, over a weft strand above the plane of the core warp strands, then under an adjacent weft strand above the plane of the core warp strands and over the neXt= adjacent weft strand above the plane of'the core warps strands and then under aweft strand beneath the plane of the core warp strands, and an adjacent face warp strand positioned above the weft strands above the plane of the; core warp strands and passing in the same manner as the first named strand .passed but over weft strands next adjacent those over which the first mentioned face warp strand passed, a pair of said face warp strands lying between adjacent core warp strands, substantially as set forth. g

8. A fabric adapted for use as a dryer canvas or felt comprising warp cores of rel-- atively straight parallel strands spaced apart and lying in a single plane without crimps,

two planes of weft strands resting on 0pposite sides of the said warp and face warp strands interlocking the weft strands and weft strands in position, to provide a relathe fabric, substantially as set forth. i

9. A fabric adapted for use as a dryer canvas or felt comprising core warp strands laid parallel and spaced apart and lying in asin gle plane, weft strands positioned on oppositeesides of the core warp with each weft strand positioned opposite the space between a pair of weft strands on the opposite sides of the core warp and face warp strands interlocking the weft strands and sorting to maintain the core war strands and the weft strands in position, t e face warp strands being so woven as to provide a relatively smooth uniform face to the fabric, and an open or corrugated back, the said face warp strands concealingthe core warp from the top but exposing the core warp on the back of the fabric, substantially as set forth.

10. A fabric adapted for use as a dryer canvas or felt comprising core war'p strands lying parallel and in the same plane, weft strands positioned in planes on the opposite sides of the plane of the core warp strands and two pair of face Warp strands, one pair lying between adjacent core warp strands and the other pair lying in the space between the next adjacent core warp strands, thesaid strands passing over two adjacent weft strands above the plane of the core and under a single weft strand below the plane of the core and thenceunder two adjacent weft strands above theplane of the core warp strands to provide a smooth uniform face to thefabrie and an open back to the same, substantialy as set forth.

11. A fabric for use as a dryer canvas or felt comprising relatively uncrimped core warp strands and weft strands lying in planes on opposite sides of the core warp .strands, and face warp strands woven over 'planes on opposite sides of the core 'warp strands, and face warp strands woven over and under the weft strands above and below the plane of the core warp and so positioned as to make an open back to provide a high degree of porosity, the core warp strands being unexposed to the face of the fabric to prevent injury to them and serving to sustain the tensile strain on the fabric with little longitudinal stretch, substantially as set forth.

13. A dryercanvas or felt comprising relatively. uncrimped core warp strands, weft v strands lying in planes on opposite sides of serving to maintain the core warp and the the core warp strands, a pair of face warp strands lying between adjacent core warp strands, one of said face warp strands passes above all the weft strands above the plane of the core warp strands but passes under alternate weft strands beneath the core warp strands, the other of said face wrap strands lying wholly above the plane over and under weft strands on bot of the core warp, the face warp strands leavof the core wa strands and passes alternately over an under the weft strands above the lane of the core warp strands, substantialiy as set forth.

14. A dryer canvas or felt comprising a woven fabric having an open back with corrugations to eifect rapid evaporation of water therefrom, and a relatively smooth uniform face, said fabric having core' warp strands lying in a plane between two planes of weft strands, face warp strands assiing s1 es ing the core warp strands practically uncrimped and so positioned as to rovide a highvdegree of porosity through t e fabric, the core warp strands being practically uncrimped minimizes the elongation of the fabric which prevents any substantial narrowing of the fabric when in use thereby main-.. tuning a substantiall constant degree of porosity throughout t e life of the fabric, substantially as set forth.

In 'tness whereof,I

have hereunto set I my hand at Baltimore, Maryland, this 5th day of May, A. D. n ineteen hundred and thirty-one.

IRA C. HOFFACKER. 

